Method of making paper



P 1929. R. B. DANIELS 1,729,571

METHOD OF hAKING PAPER 7 Filed Oct. 15, 1926 2 Sheets-Sheet l avwentz Ruper/B.@am'eb.

P' 1929- R. B. DANIELS 1,729,571

. METHOD OF MAKING PAPER Filed Oct. 15, 1926 2 Sheets-Sheet v 2 Paper/Z3, om/J.

Patented Sept. 24, 1929 UNITED STATES PATENT QFFWE RUPERT B. DANIELS, F ADAMS, MASSACHUSETTS, ASSIGNOR T0 L. L. BROWN I AIER COMPANY, OF ADAMS, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS METHOD OF MAKING PAPER Application filed October 15,

This invention relates to the art of paper making and pertains more particularly to the making of paper having certain definite portions of a thickness different from that of '5 other definite portions thereof.

It is an object of this invention to provide a method and apparatus which shall produce such paper expeditiously and efiiciently.

Other objects and advantages'of the 111- vention will appear hereinafter.

. The accompanying drawings illustrate the invention more or less semi-diagrammatlcally, Figure 1 being a plan View, Flgure 2 being a side elevation, certain parts being shown in section to better illustrate the invention, Figure 3 is a detail perspective vlew, Figure 4 is an enlarged detail view partly broken away, and Figure 5 is a section on the line 5-5 of Figure. 4.

For purposes of convenience of descript on the invention has been illustrated as appl ed to the ordinary F ourdrinier paper making machine in which the stock comprising fibrous material and water is flowed in a liquid state onto a moving wire through which the water is permitted to percolate gradually, leaving the fibrous mass form ng the we In such machines the wire is caused to travel continuously at a uniform rate and the flow of stock onto the wire is ordinarily controlled by slices or bars extending across the path of the wire, said slices being arranged to permit a substantially uniform rate of flow of stock thereunder sothat the web or paper which is formed may be of uniform thickness. g In my former Patents Nos. 1,587,700 and 1,587,699 I have described a method of forming a web of the type in which the fibrous mass constituting certain defined portions is of a different thickness from that constituting other portions thereof, by depositing the stock or pulp to form the web in a layer having difierent thicknesses at the desired difierent portions thereof. It was proposed in said patents to control the flow of stock past the usual slices in such manner as to provide one rate of flow at certain points and to provide a difi'erent rate of flow at other points, the web formed by so controlling the 1926. Serial No. 141,735.

flow of the stock having defined portions of different thicknesses. It was also proposed to maintain the difference in thickness of the .pulpy mass thus established until suificient at that point. Thereafter the areas of less thickness thus formed were maintained by applying air pressure, either in the form of a series of direct jets as disclosed in Patent No. 1,587,700 or in the form of a confined current of air as by providing a hood as disclosed in Patent No. 1,587 ,699.

It has been found, however, that for certain purposes, the desired restriction of the flow of stock under the slice may be secured without the use of a mechanical obstruction attached to the slice, if the air pressure which is used to maintain the areas of less thickness is applied in a manner to permit it to restrict somewhat the inflow of pulp under the slice at the point at which the air pressure is applied.

Referring to the drawings, liquid stock from the flow box 1 passes from the flow 85 box over the lip 2 and over the apron 3 onto the wire 4 which passes about the breast roll 4 in the usual manner. As the stock flows along in the direction of the arrows it passes under the first slice 5 which is adjusted with 90 res ect to the wire 4 in such manner as to restrict the flow of stock somewhat before passing .to the second slice 6. The second slice is arranged somewhat nearer the wire 4 than the first slice and ordinarily permits the flow of 11 is connected to a header 15 through the the areas of flexible hose 16 and the header may be connected to a suitable blower or other source of air pressure through the pipe 15.

Any suitable number of pipes 11 may be used depending upon the areas which it may be desirable to form in the sheet. One of the pipes 11 for the application of fluid pressure is provided, of course, for each portion of less thickness.

Each of the pipes 11 may be conveniently supported by the usual cross rods 17 for the deckle frames andmay be attached thereto by any suitable means. In the'present embodiment means are provided by which the pipes may be adjusted vertically with respect to the cross rods and the wire in order that the pipes may be conveniently brought into proper relationship with the web which is in the process of formation. Such means may comprise simply threaded bolts 18 passing through the straps supporting the ipes, which bolts may be turned to raise or ower the pipes as desired.

As will be apparent, the pipes 11 with their attached fins or curtains 14 form an elongated hood through which air pressure may be applied to the web. Preferably the pipe is so adjusted with respectto the wire and pulp thereof that the curtains 14 project slightly into the pulp to form a seal to prevent the escape of air along the sides thereof. The curtains 14 should not project too deeply into the pulp for best results, as it has been observed that when this occurs the fibers are sometimes disturbed by a rolling action which takes place between the lower edge of the curtains and the wire which causes undesirable efl'ects in the finished paper.

The forward end of each of the pipes 11 is arranged closely adjacent to the second slice 6 and the confined body of air therein restricts the flow of pulp under the slice in such manner that less fibers are deposited at these points. By extending the hoods in the manner illustrated for considerable distance beyond the second slice 6 and thus maintaining air pressure on the thinned portion thus formed, the inflow of fibers from reater thickness is prevented until at the en s of the hoods, sufiicient water has been removed from the pulpy material so that there is no further tendency for the fibers to flow from one area to another.

The adjustment of the air pressure applied is amatter of some importance, but due to the varying conditions encountered in manufacturingprocesses no satisfactory rule as to its amount can be given. Different rates of flow of the stock, different qualities of stock and even different atmospheric conditions may operate .to vary the air pressure required.

- The proper pressure may easily be determined by askillful operator by observance of the apparatus in operation, for the pressure applied should in no case be sufficient to cause the pulp to be extruded beneath the fins or curtains 14. In fact, in order to avoid this result with the accompanying undesirable ridge which would be formed thereby on either side of the portion of less thickness, it is preferable to reduce the air pressure to a polnt where some inflowof pulp may result, as this has no ill effect on the finished paper,

although it will be understood that the ideal condition is that in which no flow occurs in either direction.

It will be understood that the invention may be variously modified and embodied within the scope of'the subjoined claims.

I claim as myainvention:

1. The method of controlling the flow of fibers to form a paper sheet having designated areas of less thickness than the normal thickness of said sheet, which comprises restricting the flow of fibers to the areas of less thickness to a greater extent than to the areas of normal thickness by applying fluid pressure, and maintainingthe difference in thickness, until the fibers are set by continued application of fluid pressure.

2. The method of controlling the flow of fibers to form a paper sheet having designated areas of less thickness than the normal thickness of said sheet, which comprises restricting the flow of fibers to the areas of less thickness to a greater extent than tothe areas of normal thickness by applying air pressure, and maintaining the difference in thickness until the fibers are set bycontinued application of air pressure.

3. The method of controlling the flow of fibers to form a paper sheet having designated areas of less thickness than the normal thickness of said sheet, which comprises restricting the flow of fibers to the areas of less thickness to a eater extent than to the areas of normal hie ess by applying a confined current of air, and maintaining the difference in thickness until the fibers are set by continued application of said confined current of air.

4. The method of controlling the flow of fibers to form a paper sheet having designated areas of less thickness than the normal thickness of said sheet. which comprises restricting the flow of fibers to the areas of less thickness to a greater extent than to the areas of normal thickness by appiying air pressure over an area extending cm the vslice to a point at which the fibers are set.

5. The method 015 controlling the flow of fibers to form a paper sheet having designated areas of less thickness'thanethe normal thickness of said sheet, which comprises restricting the flow of fibers to the areas of less thickness to a greater extent than to the areas of normal thickness by applying air pressures thereto.

' In testimony whereof, I have signed in nameto this specification this twelfth day of 5 October, 1926.

RUPERT B. DANIELS. 

